The present invention relates generally to the separation and collection of hydrogen gas and, more particularly, to the use of membranes to prevent poisoning of gettering devices used in the collection of hydrogen gas. The invention was made with government support under Contract No. W-7405-ENG-36 awarded by the U.S. Department of Energy. The government has certain rights in this invention.
The reclamation of tritium from contaminated metals is being investigated in order to minimize tritium waste that must be buried or recovered and to save resources. Tritium in its common gaseous state can diffuse into metals so that the equipment used to handle this gas becomes contaminated. Considerable quantities of salvageable metal have been generated which, by current disposal procedures, must be cut up and buried in an appropriate disposal facility. It is known that, if such metals are heated, tritium and other gases will be released and can be pumped into recovery vessels.
The currently accepted technology for recovering tritium from tritium process systems produces tritiated water which is about 25,000 times more absorbable into the human body than is tritium gas, thereby presenting a more hazardous approach to tritium reclamation.
In W. T. Shmayda et al., "Inert Gas Secondary Enclosure Clean-Up System," Fusion Technology 21:2, 616-624 (March, 1992), the authors state that tritium removal efficiencies for zirconium-based tritides deteriorate in the presence of oxygen, carbon monoxide, water and methane. The alloy's scavenging ability may be restored by a bakeout procedure, however, if it is not already oxidized.
In H. Ito et al., "Separation Of Tritium Using Polyimide Membranes," Fusion Technology 21:2, 988-993 (March 1992), the authors identify polyimide gas membranes useful for volume reduction of tritium contaminated atmosphere by selective permeation of hydrogen. No mention is made, however, of protecting gas absorption materials from effects of impurity gases in the tritium by using such membranes.
In Okin M. Ekiner and George Vassilatos, "Polymeric Membranes," U.S. Pat. No. 5,102,600, issued Apr. 7, 1992, the inventors discuss polymeric membranes which are potentially useful for separation of hydrogen (tritium) gas from gas mixtures.
Accordingly, it is an object of the present invention to provide an apparatus for separating and collecting tritium gas in the presence of getter-passivating gases.
Another object of the invention is to provide an apparatus which is .beta.-radiation resistant for separating and collecting tritium gas.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.